Flashlight and combination for use in aligning flashlight lamp bulbs

BACKGROUND OF THE INVENTION

1. Field of the Invention

The field of the present invention relates to flashlights and flashlight components.

2. Background

Various flashlight designs are known in the art. Flashlights typically include one or more dry cell batteries. In certain designs, the batteries are arranged in series in a battery compartment of a barrel or tube that acts as a handle for the flashlight. An electrical circuit is frequently established from one electrode of the battery or batteries through a conductor to a switch, then through a conductor to one electrode of the lamp bulb. After passing through the filament of the lamp bulb, the electric circuit emerges through a second electrode of the lamp bulb in electrical contact with a conductor, which in turn is in electrical contact with the other electrode of the battery or batteries. Actuation of the switch to complete the electric circuit enables electricity to pass through the filament, thereby generating light which is typically focused by a reflector to form a beam of light.

The production of light from such flashlights has often been degraded by the quality of the reflector used and the optical characteristics of any lens interposed in the beam path. As a result, efforts at improving such flashlights have often attempted to address the quality of their optical characteristics. For example, more highly reflective, well-defined reflectors have been found to provide a better-defined focus thereby enhancing the quality of the light beam produced. Additionally, several advances have been achieved in the light emitting characteristics of flashlight lamp bulbs.

Despite such efforts, light beams produced by known flashlights are frequently elliptical or elongated in shape. These aberrations generally result from the fact that the flashlight lamp bulb is not properly aligned with the principal axis of the reflector of the assembled flashlight.

In various flashlight designs, the lamp is supported within the flashlight by a holder or spacer within the barrel and extends into the flashlight reflector. Due to manufacturing and assembly operations and tolerances, however, after manufacture of the flashlight is fully completed, the lamp may be permanently misaligned with the reflector, resulting in degraded performance. Furthermore, simply locating the center of the lamp bulb on the principal axis of the reflector does not ensure that aberrations in the projected light beam will be eliminated. This is because the critical component of the lamp that must be centered relative to the reflector is the lamp filament.

One attempt at addressing the misalignment problem is described in U.S. Pat. No. 5,260,858, by A. Maglica. This patent describes a flashlight that includes a switch housing that partially floats within the barrel of the flashlight to allow for slight movement of the lamp relative to the reflector, thereby helping to ensure that the lamp and the lamp filament are centered relative to the reflector. However, in the centering mechanism described in U.S. Pat. No. 5,260,858, to the extent that the lamp filament is not centered within the bulb, then the lamp filament will not be properly centered within the reflector and optimal performance of the flashlight will not be achieved.

Switch designs that are adapted to close an electrical path between the lamp bulb and battery, or batteries, in response to axial movement of the head along the barrel and to open the electrical path in response to axial movement in the opposite direction along the barrel are known. While such switches have generally worked well for flashlights that employ smaller batteries of the AA or AAA type, known designs are not well suited for flashlights that employ larger battery sizes, such as C or D size batteries. One reason such designs are not well suited for flashlights employing larger batteries is that the positive electrode of the battery closest to the head end of the flashlight is urged against a conductor mounted flush against the bottom of the switch. As a result, the battery or batteries may become damaged in the event that the flashlight is dropped. The problem also becomes more acute as the number of batteries connected in series increases due to the added weight, and hence momentum, of the batteries. Another reason such switch designs are not well suited for flashlights with larger batteries is that they are not designed to handle the heat associated with higher amperage lamp bulbs rated for use with such batteries.

Current switch designs that open and close in response to axial movement of the head assembly along the barrel are also not designed to ensure that the filament of each bulb will always be properly aligned with the principal axis of the reflector. As a result, optimal performance of such flashlights is not always achieved.

Misalignment problems are likely to be more pronounced in flashlights with higher capacity bulbs, because such bulbs tend to be longer, thus accentuating any misalignment between the bulb holding mechanism of the flashlight and the reflector as well as any misalignment of the bulb filament within the bulb itself.

The development of flashlights having a variable focus, which produces a beam of light having variable dispersion, has also been accomplished. In such flashlights, the head assembly is typically rotatably connected to the barrel of the flashlight at the end where the bulb is retained. In addition, the head assembly is adapted to be controllably translatable along the barrel such that the relative positional relationship between the reflector and lamp bulb may be varied, thereby varying the dispersion of the light beam emanating through the lens from the lamb bulb. While variable focus flashlights have also employed switches that are adapted to open and close in response to the axial movement of the head assembly, such flashlights have generally been limited to flashlights employing AA and AAA batteries for a variety of reasons, including some of those described above.

In metal flashlights, the flashlight's tail cap is typically a component of the electrical circuit and there must be electrical continuity from one part of the tail cap to another, usually from an outer peripheral region to an inner peripheral region. In such designs when the tail cap and the barrel are anodized, painted, or otherwise treated so that the surface of the tail cap or the barrel loses all or a part of its ability to conduct current, then extra processing steps are required to either remove the non-conducting coating from electrical contact points or mask the contact points prior to forming the coating.

In order to avoid having to remove the nonconductive coating from the contact points of the tail cap, or mask the contact points, attempts have been made to eliminate the tail cap from the electrical circuit. Several different designs have been employed to achieve this end. Such designs, however, have required the use of a plurality of parts and multiple manufacturing steps. The elimination of any such parts and steps would decrease the overall manufacturing cost of the flashlight, as well as improve the reliability of the flashlight.

SUMMARY OF THE INVENTION

It is an object of the present invention to address or at least ameliorate one or more of the problems associated with the prior art noted above.

Accordingly, in a first aspect of the present invention, it is an object to provide a device that may be used to align the filament of a lamp bulb with a reflector, particularly flashlight reflectors, although the invention is not limited to flashlight reflectors.

In accordance with this object, in a first aspect of the present invention a combination for use in aligning a flashlight lamp bulb with the principle axis of a flashlight reflector is provided. The combination includes a lamp bulb and a lamp base. The lamp bulb has a pair of electrodes and a filament extending between the electrodes. The lamp base is adapted to receive the electrodes of the lamp bulb. The lamp bulb is secured to the base so that the electrodes extend through the base, the lamp bulb is disposed adjacent the base, and the filament of the lamp bulb is aligned with a predetermined axis extending through the base. The base is configured to be seated in a bore provided in a base receiver mounted adjacent to a forward end of the flashlight so as to align the predetermined axis of the base with the principal axis of the reflector.

In accordance with the first aspect of the present invention, a combination for use in aligning the filament of a lamp bulb with the principle axis of a reflector is also provided. The combination comprises a bi-pin lamp bulb and a lamp base. The lamp bulb has a bulb portion, a pair of electrodes and a filament extending between the electrodes. The lamp base comprises a conical frustum having a circular base end, a circular truncated end parallel to and concentric with the base end, and a conical-shaped side wall interposed between the two. The lamp base further includes two holes extending through the base in a direction parallel to an axis extending through the center of the base end and truncated end and adapted to receive the electrodes of the lamp bulb. The lamp bulb is secured to the base so that the electrodes extend through the base, the bulb portion is disposed adjacent the base, and the filament of the lamp bulb is aligned with the axis.

In yet another embodiment of the first aspect of the invention, a combination is provided that comprises a lamp bulb, a lamp base, a reflector, and a lamp base receiver. The lamp bulb includes a pair of electrodes and a filament extending between the electrodes. The lamp bulb is secured to the lamp base so that the center of the filament is aligned with a predetermined axis of the lamp base. The lamp base is adapted to receive the lamp base receiver and align the predetermined axis of the lamp base with the principal axis of the reflector.

The lamp base may include a tapered surface concentric about the predetermined axis, and the tapered surface may be seated against a matching tapered surface provided in the lamp base receiver that is concentric about the principal axis of the reflector.

In another aspect of the invention, a method of manufacturing a lamp bulb and lamp base combination is provided. The method comprises the steps of first obtaining a lamp bulb having a bulb portion, a pair of electrodes extending from the bulb portion, and a filament extending between the electrodes within the bulb portion. The lamp bulb is then inserted into a lamp base adapted to receive the electrodes of the lamp bulb until the bulb portion of the lamp bulb is adjacent the base and the electrodes extend through the base. The lamp base is adapted to permit lateral movement of the bulb portion and electrodes with respect to a predetermined axis extending through the lamp base. The lamp bulb is then laterally adjusted with respect to the predetermined axis of the base until the filament of the lamp bulb is aligned with the predetermined axis. The lamp bulb is then secured to the lamp base to preserve the alignment of the filament with the predetermined axis.

In yet another aspect of the invention it is an object to provide a flashlight with improved optical characteristics. The flashlight includes a barrel for retaining one or more batteries. A head assembly is mounted to a first end of the barrel. The head assembly includes a lens and a reflector having a central opening surrounding the principal axis of the reflector. A lamp bulb having a filament extending between two electrodes is secured to a lamp base so that the lamp bulb is disposed adjacent the base and the filament of the lamp bulb is aligned with a predetermined axis extending through the base. A lamp base receiver is mounted adjacent the first end of the barrel. The lamp base is removably seated in a complementary bore extending through the lamp base receiver, and the lamp base receiver is mounted adjacent the first end of the barrel so that the lamp bulb extends through the central opening in the reflector and the predetermined axis of the lamp base is aligned with the principal axis of the reflector. A tail cap is attached to the second end of the barrel. An electrical circuit couples the electrodes of the lamp bulb to the one or more batteries. A switch is interposed in the electrical circuit for turning the flashlight on and off.

In still another aspect of the invention, it is an object to provide a new tail cap assembly for a flashlight having a barrel with a forward end and a rearward end. The tail cap assembly comprises a tail cap comprising a first body portion having a first end and a second end and being adapted to removably engage the interior of the flashlight barrel at the rearward end. A second body portion is attached to the second end of the first body portion and is adapted to enclose the rearward end of the flashlight barrel when the first body portion engages the barrel. A spring seat is provided at the first end of the first body portion, and may comprise a pair of spaced apart, opposing ears, with opposing gaps provided at the ends of the opposing ears. The tail cap assembly further includes a conductive spring that includes a base portion removably retained between the opposing ears of the spring seat. The base portion is adapted to extend outward in a radial direction through the opposing gaps provided between the ears so as to make physical contact with the inner surface of the barrel when the tail cap is engaged with the barrel.

In still another aspect of the invention, it is an object of the invention to provide a new design for a flashlight that does not require the tail cap to be included in the electrical circuit. The flashlight includes a barrel for retaining a battery source of power and having first and second ends. The barrel further comprises an electrically conductive material. A bulb is positioned at the first end of the barrel. A tail cap is removably engaged with the interior of the second end of the barrel. The tail cap includes a spring seat positioned on the interior of the barrel. The spring seat comprises a pair of opposing ears spaced apart from the axis of the barrel. A conductive spring is disposed between the tail cap and a case electrode of the battery source of power. The conductive spring includes a base portion removably retained between the opposing ears of the spring seat and which is adapted to extend outward in a radial direction through opposing gaps provided between the ears so as to make physical contact with the inner surface of the barrel when the tail cap is engaged with the barrel. In addition, the spring serves to provide a direct electrical path between the case electrode of the battery source of power and the barrel. The flashlight further comprises an electrical circuit coupling the bulb to the battery source of power that includes the direct electrical path provided by the spring between the case electrode and barrel. A switch is interposed in the electrical circuit to turn the flashlight on and off.

The above and other objects, features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a flashlight in accordance with the present invention.

FIG. 2 is an exploded perspective view of the flashlight of FIG. 1 where the tail cap assembly and head assembly both have been disengaged from the barrel.

FIG. 3 is a cross-sectional view of the flashlight of FIG. 1 as taken through the plane indicated by <b>3</b>—<b>3</b> where the switch is shown in the “off” position.

FIG. 3A is an enlarged view of the portion of the flashlight shown in FIG. 3 that is encircled by circle <b>3</b>A.

FIG. 4 is an enlarged cross-sectional view of the forward end of the flashlight of FIG. 1 as taken through the plane indicated by <b>3</b>—<b>3</b> where the switch is shown in the “on” position.

FIG. 5 is an enlarged cross-sectional view of the tail cap assembly of the flashlight of FIG. 1 taken through a plane rotated 90 degrees from the plane indicated by <b>3</b>—<b>3</b> and is provided in order to better illustrate one of the aspects of the present invention.

FIG. 6 is a cross-sectional view of the flashlight of FIG. 1 as taken through the plane indicated by <b>3</b>—<b>3</b> without including batteries.

FIG. 7 is an exploded perspective view from the forward end of the flashlight of FIG. 1 illustrating the assembly of a preferred switch and a preferred bulb alignment mechanism in accordance with two separate aspects of the present invention with respect to the barrel of the flashlight.

FIG. 8 is an exploded perspective view from the rearward end of the flashlight of FIG. 1 illustrating the assembly of the preferred switch and bulb alignment mechanism with respect to the barrel of the flashlight.

FIG. 9 is a view of the switch of FIG. 7 from the forward end of the flashlight.

FIG. 10 is a view of the rearward end of the switch.

FIG. 11 is an enlarged, exploded perspective view of an embodiment of a bi-pin lamp bulb and lamp base combination according to an aspect of the present invention.

FIG. 12 is an enlarged, exploded perspective view of the bi-pin lamp bulb and the lamp base combination shown in FIG. 11 as viewed from the base end of the combination.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring first to FIG. 1, a flashlight in accordance with a preferred embodiment of the present invention is illustrated in perspective, generally at <b>20</b>. The flashlight illustrated in FIG. 1 incorporates a number of distinct aspects of the present invention. These distinct aspects have all been incorporated into the flashlight <b>20</b> that is described in detail below and illustrated in the accompanying figures for the purpose of illustrating a preferred embodiment of the invention. It is to be expressly understood, however, that the present invention is not restricted to flashlights that incorporate all of the distinct aspects of the present invention described herein. Rather, the present invention includes flashlights that incorporate one or more of the separate aspects of the invention. It is also to be understood that the present invention is also directed to each of the separate aspects of the flashlight described below.

The flashlight <b>20</b> is comprised of a barrel <b>21</b> enclosed at a rearward end by a tail cap <b>22</b> and having a head assembly <b>23</b> enclosing a forward end thereof. The head assembly of the present embodiment comprises a head <b>24</b> to which is affixed a face cap <b>25</b> which retains a lens <b>26</b>. As best seen in FIG. 3, the head assembly <b>23</b> has a diameter greater than that of the barrel <b>21</b> and is adapted to pass externally over the exterior of the barrel <b>21</b>. As is known in the art, barrel <b>21</b> may be provided with a textured surface <b>27</b> along its axial extent, preferably in the form of machined knurling.

Referring next to FIG. 2, the flashlight <b>20</b> is shown in perspective with the tail cap assembly <b>28</b> and head assembly <b>23</b> both disengaged from the barrel <b>21</b>.

One distinct aspect of the present invention relates to the tail cap assembly <b>28</b>. As shown in FIGS. 2, <b>3</b>, <b>5</b>, and <b>6</b> tail cap assembly <b>28</b> of the present embodiment includes tail cap <b>22</b> and conductive spring member <b>34</b>. Tail cap assembly <b>28</b> also preferably includes a removable spare bulb holder <b>29</b> disposed in a cavity that opens to the end of the tail cap that engages barrel <b>21</b>. Removable spare bulb holder <b>29</b> includes an inner hub that frictionally retains the spare lamp bulb <b>59</b>. As shown, for example, in FIGS. 2 and 3, spokes <b>52</b> extend from the inner hub <b>54</b> to an outer hub <b>56</b> in frictional contact with the inner surface of the cavity formed in tail cap <b>22</b> to prevent damage to the spare lamp bulb <b>59</b>.

Tail cap <b>22</b> also preferably includes a region of external threads <b>32</b> for engaging matching threads formed on the interior of the barrel <b>21</b>. However, other suitable means may also be employed for attaching tail cap <b>22</b> to barrel <b>21</b>. A sealing element <b>33</b> may be provided at the interface between the tail cap <b>22</b> and the barrel <b>21</b> to provide a watertight seal. As best seen in FIGS. 3 and 5, sealing element <b>33</b> is preferably a one-way valve <b>62</b> in the form of a lip seal. However, as those skilled in the art will appreciate, it may also comprise an O-ring. One way valve <b>62</b> is retained in a circumferential channel <b>44</b> formed in tail cap <b>22</b>. One-way valve <b>62</b> is oriented so as to prevent flow from outside into the interior of the flashlight <b>20</b>, while simultaneously allowing overpressure within the flashlight to escape or vent to the atmosphere.

Threads <b>32</b> may be provided with a flattened top so as to create a spiral passage through the mating threads between the barrel <b>21</b> and the tail cap <b>22</b>. Additionally, radial spines <b>46</b> may be formed in a mating flange of the tail cap <b>21</b> as shown in FIG. 2 to ensure that the end of barrel <b>21</b> does not provide a gas tight seal against the associated flange, thereby impeding the flow of overpressure gases from the interior of the flashlight.

The design and use of one-way valves in flashlights is more fully described in U.S. Pat. No. 5,113,326 to Anthony Maglica, which is hereby incorporated by reference.

The barrel <b>21</b> is seen to have an extent sufficient to enclose at least two dry cell batteries <b>31</b> disposed in a series arrangement. It will be appreciated by those skilled in the art, however, that barrel <b>21</b> may also be configured to include a single battery or a plurality of two or more batteries in either a series or a side-by-side arrangement. Furthermore, while batteries <b>31</b> may comprise any of the known battery sizes, flashlight <b>20</b> according to the illustrated embodiment is particularly well suited for C or D sized batteries.

In a particularly preferred aspect of the present invention, the spring member <b>34</b> is disposed within the barrel <b>21</b> so as to form a direct electrical path between a case electrode <b>35</b> of an adjacent battery <b>31</b> and the inner surface <b>30</b> of the barrel <b>21</b>. In alternative implementations of the invention, however, spring member <b>34</b> may also, or in the alternative, form an electrical path between the tail cap <b>22</b> and case electrode <b>35</b> of the rearmost battery <b>31</b>.

The spring member <b>34</b> also urges the batteries <b>31</b> in a direction indicated by arrow <b>36</b>. As a result, a center electrode <b>37</b> of the rearmost battery <b>31</b> is in electrical contact with the case electrode of the forwardmost battery <b>31</b>, and the center electrode <b>38</b> of the forwardmost battery <b>31</b> is urged into contact with a first conductor <b>39</b> of switch <b>40</b>.

Switch <b>40</b> constitutes another aspect of the present invention. Switch <b>40</b> is provided to open and close an electrical path between the batteries and one of the electrodes of lamp bulb <b>59</b>. Thus, switch <b>40</b> allows the flashlight <b>20</b> to be selectively turned on and off.

Switch <b>40</b> is adapted to close the electrical path between the lamp bulb and batteries in response to axial movement of the head along the barrel and to open the electrical path in response to axial movement of the head in the opposite direction. It will be appreciated, however, that other types of switches that are commonly used in flashlights may also be employed with the other aspects of the invention described herein.

As best seen in FIGS. 7 and 8, switch <b>40</b> comprises the first conductor <b>39</b>, a lower insulator <b>41</b>, a second conductor <b>42</b>, and an upper insulated retainer <b>48</b>.

Referring to FIGS. 3, <b>4</b>, and <b>6</b>-<b>10</b>, lower insulator <b>41</b> includes a sidewall <b>43</b> that defines a right circular cylinder. The diameter of the cylindrical wall defined by the sidewall <b>43</b> is dimensioned so that the lower insulator <b>41</b> may slide up and down against the inner surface <b>30</b> of barrel <b>21</b> without binding. At the same time, the diameter of the lower insulator is sufficient to prevent side-to-side movement of the lower insulator within the barrel. In addition, the lower insulator is preferably of sufficient length to prevent it from tilting with respect to the barrel. As a result of the foregoing arrangement, lower insulator <b>41</b> and barrel <b>21</b> will remain coaxial with respect to one another.

The first conductor <b>39</b> is mounted within a recess <b>45</b> formed in the bottom of insulator <b>41</b>. The first conductor <b>39</b> is a resilient spring conductor adapted to be compressible in the direction of arrow <b>36</b>. Conductor <b>39</b> is configured so that when mounted within recess <b>45</b> it does not extend beyond sidewall <b>43</b> of the lower insulator <b>41</b>. As a result, if batteries <b>31</b> are inserted backwards into barrel <b>21</b>, so that their case electrodes are pointing forward, an electrical circuit is not formed. When the batteries are inserted correctly as shown in FIG. 3, however, the center electrode of the forwardmost battery is urged into contact with, and compresses, the first conductor <b>39</b>.

Sidewall <b>43</b> is sized to abut against an end <b>51</b> of battery casing <b>53</b> of the forwardmost battery for a given size battery. In addition, the central portion of recess <b>45</b> is dimensioned to be deeper than the distance center electrode <b>38</b> extends beyond the end of the battery casing for the given size battery. As flashlight barrel <b>21</b> is typically sized to accommodate specific standard size batteries <b>31</b>, the lower insulator <b>41</b> will also be appropriately located within the barrel <b>21</b> to abut against end <b>51</b> of battery casing <b>53</b>. In view of the foregoing relationships, the switch of the present embodiment helps to avoid impact stresses on the center electrode <b>38</b> of the forwardmost battery.

The first conductor <b>39</b> preferably comprises a leaf spring which allows limited travel of the batteries towards and away from the switch assembly without losing physical or electrical contact between the center electrode <b>38</b> of the forwardmost battery <b>31</b> and the first conductor <b>39</b>. The spring action of conductor <b>39</b> provides a dampening effect that further helps to prevent damage to the center electrode <b>38</b> in the event the flashlight is dropped; it also helps to maintain electrical contact in such situations.

First conductor <b>39</b> includes a first contact <b>55</b> that is disposed in a slot <b>47</b> provided in a support pedestal <b>50</b> formed in the central region of recess <b>45</b>. Slot <b>47</b> extends in an axial direction and is in communication with hole <b>49</b> provided in the forward surface of the insulator receptacle <b>41</b>. As a result, a first terminal electrode <b>57</b> of a lamp bulb <b>59</b>, for example a bi-pin lamp bulb, may extend through hole <b>49</b> into slot <b>47</b>. Contact <b>55</b> is adapted to frictionally receive and retain electrode <b>57</b> of the lamp bulb <b>59</b>.

The first conductor <b>39</b> may be integrally formed from a strip of resilient metal of suitable width by stamping appropriate cuts in the strip and then bending the cut strip. The first conductor <b>39</b> is preferably formed to have a base arm <b>61</b> and a leaf spring arm <b>63</b> with a circular loop <b>65</b> connecting the two at one end. Loop <b>65</b> urges leaf spring <b>63</b> away from base arm <b>61</b>. Hooks <b>67</b> are provided at the end of the leaf spring arm <b>63</b> that is opposite loop <b>65</b> to grip onto the corresponding end of the base arm <b>61</b>. As best seen in FIG. 6, hooks <b>67</b> keep leaf spring <b>63</b> from springing to its relaxed position in the absence of a compressive force being applied by batteries <b>31</b> in the direction of base arm <b>61</b>. Thus, hooks <b>67</b> maintain a desired spacing between base arm <b>61</b> and leaf spring arm <b>63</b> in the absence of an external force. The spacing between leaf spring <b>63</b> and base arm <b>61</b> is advantageously sized to be greater than the distance center electrode <b>38</b> extends beyond the end of the battery casing for the size of battery for which flashlight <b>20</b> is designed. As a result, center electrode <b>38</b> of battery <b>31</b> will not contact base arm <b>61</b>, which is rigidly supported by support pedestal <b>50</b> formed in recess <b>45</b>, again helping to avoid impact stresses on the center electrode <b>38</b> of the battery.

The first conductor <b>39</b> may be secured within recess <b>45</b> in a variety of ways. In the present embodiment, conductor <b>39</b> is secured within recess <b>45</b> by appropriately shaping circular loop <b>65</b> and providing conductor <b>39</b> with first and/or second tabs <b>69</b>, <b>71</b>.

As best seen in FIG. 6, loop <b>65</b> is preferably formed so as to impart a kidney-like shape to conductor <b>39</b>. As a result, loop <b>65</b> extends into a first portion <b>73</b> of recess <b>45</b> provided between a first sidewall <b>79</b> of support pedestal <b>50</b> and the inner surface of sidewall <b>43</b>. Loop <b>65</b> is also preferably dimensioned so that its opposing sides are compressed between support pedestal <b>50</b> and the inner surface of sidewall <b>43</b>. A first tab <b>69</b> may be provided on the outer circumference of loop <b>65</b> adjacent support pedestal <b>50</b> to engage a ledge <b>77</b> provided in sidewall <b>79</b> when loop <b>65</b> is fully inserted into the portion <b>73</b> of recess <b>45</b>. When tab <b>69</b> engages ledge <b>77</b> base arm <b>61</b> should be abutting support pedestal <b>50</b> and contact <b>55</b> should be fully inserted into slot <b>47</b>. The foregoing configuration permits the loop end of conductor <b>39</b> to be mechanically fastened to support pedestal <b>50</b> in a durable manner.

The end of base arm <b>61</b> opposite loop <b>65</b> may be secured to lower insulator <b>41</b> with the aid of tab <b>71</b>. For example, as best seen in FIG. 10, tab <b>71</b> may be sized to engage the inner surface of sidewall <b>43</b> to frictionally hold the base arm to lower insulator <b>41</b>. Thus, by appropriately dimensioning base arm <b>61</b> and tab <b>71</b>, the end of conductor <b>39</b> opposite loop <b>65</b> may also be mechanically fastened within recess <b>45</b> while still permitting leaf spring arm <b>63</b> to be freely compressed.

As illustrated in FIGS. 3-4, when leaf spring arm <b>63</b> is compressed, hooks <b>67</b> generally translate in an axial direction into a second portion <b>75</b> of recess <b>45</b> provided between a second side <b>81</b> of support pedestal <b>50</b> and the inner surface of sidewall <b>43</b>.

Conductor <b>39</b> may also be secured within recess <b>45</b> by sizing slot <b>47</b> to frictionally receive contact <b>55</b>.

Second conductor <b>42</b> is adapted to provide an electrical conduction path between the second terminal electrode <b>58</b> of lamp bulb <b>59</b> and barrel <b>21</b> when switch <b>40</b> is closed. To achieve the desired conduction path, in the present embodiment, second conductor <b>42</b> is interposed between the lower insulator <b>41</b> and the upper retainer <b>48</b>. In addition, the second conductor <b>42</b> is configured so that a second contact <b>83</b>, which may be formed integrally with conductor <b>42</b>, is received in a slot <b>85</b> provided in the forward surface of insulator <b>41</b>. Slot <b>85</b> extends in an axial direction of the insulator and is generally offset from the axis of insulator <b>41</b> an appropriate distance for receiving the second terminal electrode <b>58</b> of lamp <b>59</b> while still allowing the filament <b>60</b> of the lamp to be centered on the axis of the insulator. Contact <b>83</b>, which is received in slot <b>85</b>, is adapted to frictionally receive and retain terminal <b>58</b> within the slot.

If desired, slot <b>85</b> may be sized to frictionally receive contact <b>83</b> to facilitate assembly of switch <b>40</b>.

As best illustrated in FIGS. 7 and 8, second conductor <b>42</b> also preferably includes a central body portion <b>89</b> and one or more arms <b>87</b> that extend from the central body portion in a radial direction toward the sidewall <b>43</b> of insulator <b>41</b>. Arms <b>87</b> are configured to make electrical contact with barrel <b>21</b> when switch <b>40</b> is closed. For example, in the present embodiment, three arms <b>87</b> are spaced symmetrically 120° apart and are configured to come into contact with lip <b>95</b> of barrel <b>21</b> when switch <b>40</b> is closed.

Central body portion <b>89</b> is preferably interposed between lower and upper insulators <b>41</b>, <b>48</b> so that it is orthogonal to the central axis of the lower insulator <b>41</b>, and thus flashlight <b>20</b>. To help orient conductor <b>42</b> relative to insulator <b>41</b>, central body portion <b>89</b> may include a hole <b>91</b> that axially extends through the conductor for receiving a mating protrusion or pedestal <b>84</b> provided on the forward surface of insulator <b>41</b>. For example, in the present embodiment, hole <b>91</b> is generally shaped like a segment of a circle, and pedestal <b>84</b> has a cross-sectional profile that matches the shape of hole <b>91</b>. As a result, once pedestal <b>84</b> is received in hole <b>91</b>, conductor <b>42</b> is prevented from rotating relative to insulator <b>41</b>. Although hole <b>91</b> and pedestal <b>84</b> of the present embodiment employ the shape of a segment of a circle, it will be appreciated by those skilled in the art that a wide variety of other shapes may also be used.

In the present embodiment, contact <b>83</b> is attached to central body portion <b>89</b> at the midpoint of the chord that defines the hole <b>91</b>. A protrusion <b>93</b> may be provided opposite contact <b>83</b> along the arc that defines the hole <b>91</b>. If protrusion <b>93</b> is included on conductor <b>42</b>, it is preferably configured to be received by a mating hole <b>86</b>, and thus may be used to further help properly orient conductor <b>42</b> relative to insulator <b>41</b>.

As best seen in FIGS. 4 and 7, the forward surface of insulator <b>41</b> is preferably recessed relative to a leading edge <b>97</b>. Edge <b>97</b> may be annular in shape and is preferably formed so that it is concentric with sidewall <b>43</b>. A beveled edge <b>99</b> preferably extends radially between sidewall <b>43</b> and leading edge <b>97</b>. Beveled edge <b>99</b> may be beveled at a wide variety of angles. However, an angle of approximately 45° with respect to the central axis of the insulator <b>41</b>, and thus barrel <b>21</b>, is preferred.

Central body portion <b>89</b> of conductor <b>42</b> is positioned adjacent the recessed forward surface of insulator <b>41</b>. As a result, arms <b>87</b> angle forward from central body portion <b>89</b> toward the leading edge <b>97</b> of insulator <b>41</b>. The ends of each arm <b>88</b> are bent to form a barrel contact <b>88</b> that is configured to cup around leading edge <b>97</b> and rest against beveled edge <b>99</b>.

Absent further assembly, the lower insulator <b>41</b> is urged to move in the direction indicated by the arrow <b>36</b>, by the action of the spring member <b>34</b>, until barrel contacts <b>88</b> come into contact with lip <b>95</b> of the barrel <b>21</b>. To minimize resistance and maximize contact area, lip <b>95</b> is preferably angled at the same angle as beveled edge <b>99</b> with respect to the central axis of the flashlight. In addition, lip <b>95</b> and edge <b>99</b> preferably form an acute angle with respect to the central axis of the flashlight so that the contact area of contacts <b>88</b> can be increased for a given distance that lip <b>95</b> extends radially in towards the axis of the flashlight.

Upper insulated retainer <b>48</b> is partially disposed external to the end of the barrel <b>21</b> whereat the lower insulator <b>41</b> is installed. Retainer <b>48</b> is configured to attach to lower insulator <b>41</b> and to prevent axial movement of the lower insulator <b>41</b> in a direction opposite arrow <b>36</b> beyond a predetermined distance from lip <b>95</b>. Thus, insulated retainer <b>48</b> keeps lower insulator <b>41</b> from falling to the rear of barrel <b>21</b>, and potentially out the tail end of the flashlight, in the absence of batteries <b>31</b> being installed in the flashlight. In addition, the rearward facing surface <b>108</b> of retainer <b>48</b> is adapted to press the central body portion <b>89</b> of conductor <b>42</b> firmly against the forward surface of the lower insulator, and the forward facing surface is adapted to engage reflector <b>101</b>. By pushing the central body portion <b>89</b> against the forward recessed surface, the upper insulated retainer <b>48</b> also pulls the barrel contacts <b>88</b> firmly against beveled edge <b>99</b>. As a result, switch <b>40</b> will only activate, as will be more fully described below, when head assembly <b>23</b> is rotated by a desired amount relative to barrel <b>21</b>.

In the present embodiment, the upper insulated retainer <b>48</b> comprises an annular body <b>105</b> having a central hole <b>106</b> extending therethrough. Body <b>105</b> is generally dimensioned so that it can be received within the inner diameter of lip <b>95</b> up to a rim <b>107</b>, which has a larger diameter than the inner diameter of lip <b>95</b> and which is formed on the forward end of the retainer <b>48</b>. Body <b>105</b> is also configured to provide a predetermined amount of spacing between rim <b>107</b> and beveled edge <b>99</b> when retainer <b>48</b> is attached to lower insulator <b>41</b>.

A plurality of extensions, or legs, <b>109</b> extend from the rear-facing surface <b>108</b> of the annular body for attaching retainer <b>48</b> to lower insulator <b>41</b>. Three extensions are employed in the present embodiment, with each extension being spaced 120 degrees from the other extensions so as to be in alignment with and pass through holes <b>92</b> provided in each arm of the second conductor <b>42</b>. In addition, extensions <b>109</b> are configured to mate with corresponding bores <b>111</b> provided in the lower insulator <b>41</b>. Extensions <b>109</b> and bores <b>111</b> are preferably sized to provide an interference fit between the two. The interference fit may be sufficiently strong to prevent switch <b>40</b> from being dismantled without its destruction. However, the interference fit need only be strong enough to keep switch <b>40</b> from coming apart during normal usage of the flashlight.

While retainer <b>48</b> is attached to lower insulator <b>41</b> in the present embodiment using legs <b>109</b> and bores <b>111</b>, it will be appreciated by those skilled in the art that other suitable means of attachment may also be employed. For example, legs <b>109</b> may alternatively extend from the forward surface of lower insulator <b>41</b> and bores <b>111</b> may be provided in retainer <b>48</b>.

The forward facing surface of retainer <b>48</b> is provided with a shoulder <b>113</b> for engaging reflector <b>101</b>. Shoulder <b>113</b> is shaped like an annulus in the present embodiment. A recessed surface <b>115</b> that extends concentrically inward from the inner diameter of shoulder <b>113</b> may also be provided on the forward facing surface to accommodate a central portion of the reflector <b>101</b>.

Lamp bulb <b>59</b> may be directly mounted to switch <b>40</b> so that the electrodes <b>57</b> and <b>58</b> are in electrical contact with the first and second contacts <b>55</b> and <b>83</b> of the first and second conductors. In the present embodiment, however, a lamp bulb and lamp base combination <b>121</b> according to a preferred aspect of the present invention is employed together with a lamp base receiver <b>119</b> to ensure that the filament <b>60</b> of lamp bulb <b>59</b> is aligned with the principal axis <b>123</b> of the flashlight's reflector <b>101</b>.

As shown in the exploded views of combination <b>121</b> provided in FIGS. 11 and 12, combination <b>121</b> comprises lamp <b>59</b> and lamp base <b>125</b>.

Lamp bulb <b>59</b> may be a standard bi-pin lamp bulb. Typically lamp bulb <b>59</b> will include a bulb portion <b>129</b> at one end that contains the light emitting filament <b>60</b>. The other end of the lamp bulb includes a glass bead <b>131</b> for sealing the bulb end. The first and second terminal electrodes <b>57</b> and <b>58</b> extend through the glass bead and into the bulb portion. The opposing ends of filament <b>60</b> are attached to the ends of electrodes <b>57</b> and <b>58</b> that extend into the bulb portion of the lamp.

During operation of lamp <b>59</b>, the hottest portion of filament <b>60</b>, and thus that portion which emits the most light, will occur at the middle of the overall length of the wire filament extending between the ends of the electrodes, hereinafter referred to as the “center” of the filament. However, the center of the filament is oftentimes not located on the axis of the lamp bulb. This may be due to a number of factors. For example, the filament may be more tightly wound at one end versus the other end, thus shifting the center of the filament closer to the end of one electrode than the end of the other electrode and closer to one side of the lamp bulb. Even if the filament is uniformly wound, the filament may be attached to electrodes <b>57</b>, <b>58</b> so that its center is not aligned with the axis of the lamp bulb. Furthermore, even if the center of the filament <b>60</b> is properly positioned equidistant between the ends of the electrodes <b>57</b>, <b>58</b>, misalignment may occur if the ends of the electrodes themselves are not equally spaced from the axis of the lamp bulb or if the ends of the electrodes are not properly positioned on a common plane with the central axis of the lamp bulb.

Similar misalignment problems are experienced with other types of bulbs used in the flashlight art.

Lamp bulb <b>59</b> is secured to base <b>125</b> so that the filament is centered on, or aligned with, a predetermined axis extending through the base <b>125</b>. Base <b>125</b> preferably comprises a body of revolution. In the present embodiment, as shown in FIGS. 11 and 12, base <b>125</b> generally comprises a frustum of a right circular cone having a base end <b>133</b>, a truncated end <b>135</b> parallel to the base end, and a tapered sidewall <b>137</b>. Two holes <b>139</b> extend through the base <b>125</b> in the direction of the axis of revolution <b>141</b> for receiving electrodes <b>57</b>, <b>58</b>. The lamp base <b>125</b> may be manufactured from a ceramic to prevent melting of the lamp base from the high temperatures generated by some bulbs during operation of the flashlight, as well as to insulate electrodes <b>57</b> and <b>58</b> from one another.

Axis <b>141</b> comprises the predetermined axis in the present embodiment. Accordingly, tapered surface or sidewall <b>137</b> is concentric about the predetermined axis. Holes <b>139</b> are preferably offset from axis <b>141</b> by equal distances. Holes <b>139</b> are also preferably formed in base <b>125</b> so that the axis of holes <b>139</b> fall on a common plane with axis <b>141</b> of base <b>125</b>.

The terminal electrodes <b>57</b>, <b>58</b> of the lamp bulb <b>59</b> extend through holes <b>139</b> and the end of glass bead <b>131</b> opposite bulb portion <b>129</b> is disposed adjacent to the base end of lamp base <b>125</b>.

Because the location of the center of filament <b>60</b> will vary from lamp bulb to lamp bulb with respect to the central axis of lamp bulb <b>59</b>, in the present embodiment holes <b>139</b> in base <b>125</b> are sized to have an inner diameter that is greater than the diameter of electrodes <b>57</b>, <b>58</b>. Sufficient clearance or play is provided by holes <b>139</b> to permit bulb <b>59</b> to be laterally adjusted with respect to the predetermined axis <b>141</b> of base <b>125</b> during the manufacturing alignment process so as to bring the center of filament <b>60</b> in alignment with the predetermined axis.

To align the center of filament <b>60</b> with the predetermined axis <b>141</b>, lamp bulb <b>59</b>, for example a bi-pin lamp bulb, is initially inserted into base <b>125</b> so that electrodes <b>57</b>, <b>58</b> extend through holes <b>139</b> and the glass bead portion <b>131</b> of the lamp bulb is adjacent the base end <b>133</b> of the base. Lamp bulb <b>59</b> is then laterally adjusted or displaced with respect to base <b>125</b> to bring the center of filament <b>60</b> into alignment with the predetermined axis <b>141</b>. In the present embodiment, the play between the inner walls of holes <b>139</b> and electrodes <b>57</b>, <b>58</b> permits limited side-to-side movement in all lateral directions. The lateral adjustment may be carried out manually or by an automated means. Further, an optical bench or other suitable means known in the optics art may be used to determine when filament <b>60</b> is properly aligned with the predetermined axis <b>141</b>. Preferably the filament is aligned so that its center is displaced 0.003 inches or less from the predetermined axis <b>141</b>, and more preferably 0.001 inches or less from the predetermined axis. Lamp bulb <b>59</b> is preferably powered during the alignment process to facilitate identification of the center of the filament and its alignment with axis <b>141</b>. If lamp bulb <b>59</b> is powered during the alignment process, the optical equipment employed in the optical bench is preferably adapted, as will be appreciated by those skilled in the art, to detect the hottest or brightest portion of filament <b>60</b>, and hence its center. once the filament is properly aligned with axis <b>141</b>, lamp bulb <b>59</b> may be secured or attached to base <b>125</b> using an adhesive or other suitable means to preserve the alignment of the center of the filament <b>60</b>. Although a variety of adhesives may be used, a fast, UV curing adhesive is preferred so that once filament <b>60</b> is aligned with predetermined axis <b>141</b>, the adhesive may be rapidly cured by exposing it to a UV light source. The adhesive may be applied to the base or opposing surface of glass bead <b>131</b> prior to insertion of the electrodes into base <b>125</b>. Alternatively, the adhesive may be applied subsequent to the insertion of electrodes <b>57</b>, <b>58</b> into base <b>125</b>. If the adhesive is applied prior to insertion of lamp bulb <b>59</b> into base <b>125</b>, however, obviously it should have a sufficient set time to permit the center of the filament <b>60</b> to be aligned with the predetermined axis before setting.

Base <b>125</b> of the lamp bulb and lamp base combination <b>121</b> is removably seated in a complementary bore <b>143</b> that extends through the lamp base receiver <b>119</b>, which is mounted adjacent the forward end of barrel <b>21</b>, and hence a central opening provided in reflector <b>101</b> coaxial with the principal axis of the reflector. Thus, for example, in the present embodiment the forward end portion of bore <b>143</b> is provided with a hollow conical shape, the slope of which matches the taper of sidewall <b>137</b> of base <b>125</b>.

Lamp base receiver <b>119</b> is mounted adjacent the forward end of flashlight <b>20</b> so that lamp bulb <b>59</b> extends through the central opening in the reflector and the predetermined axis of base <b>125</b>, and thus the center of filament <b>60</b>, is aligned with the principal axis <b>123</b> of the reflector <b>101</b> when the flashlight is fully assembled. Because the principal axis of reflector <b>101</b> coincides with the central axis of barrel <b>21</b> in the present embodiment, this may be accomplished in the present embodiment by mounting lamp base receiver <b>119</b> adjacent the forward end of barrel <b>21</b> so that the central axis of bore <b>143</b> is aligned with the central axis of barrel <b>21</b>, and hence the principal axis of reflector <b>101</b>. In this configuration, the tapered surface that defines bore <b>143</b> will be concentric about the principal axis of the reflector. Because the matching tapered surface of sidewall <b>137</b> of base <b>125</b> is concentric about the predetermined axis, when the tapered surface of base <b>125</b> is seated against the matching tapered surface defining bore <b>143</b>, the predetermined axis will be aligned with the principal axis.

Lamp base <b>125</b> comprises a frustum of a right circular cone. A tapered base, such as the frustum shown in the accompanying drawings, has self-centering characteristics provided by the mating tapered surfaces of the base and bore <b>143</b>. While sidewall <b>137</b> may be tapered over a wide range of angles with respect to the axis of revolution <b>141</b>, the greater the angle the more difficult it becomes to maintain filament <b>60</b> on center with the axis of bore <b>143</b> when base <b>125</b> is seated in bore <b>143</b>. As a result, sidewall <b>137</b> is preferably tapered at an angle of between 5° and 60° with respect to the axis of revolution. More preferably, sidewall <b>137</b> is tapered at an angle of between 5° and 20° with respect to the axis of revolution. Regardless of the angle of taper for sidewall <b>137</b>, however, complementary bore <b>143</b> should have a matching slope.

In the present embodiment, lamp base receiver <b>119</b> includes a base portion <b>145</b> and a tubular extension <b>146</b> projecting from the forward surface of the base portion and having a cylindrical outer surface. Bore <b>143</b> extends in an axial direction through the tubular extension and base portion. The outer diameter of tubular extension <b>146</b> is sized to slide within the central opening provided in reflector <b>101</b>.

Receiver <b>119</b> is mounted on the forward end of barrel <b>21</b> in the present implementation of the invention by interposing base portion <b>145</b> between retainer <b>48</b> and lower insulator <b>41</b>. To ensure that the central axis of bore <b>143</b> is aligned with the axis of barrel <b>21</b>, the forward facing surface, rear facing surface or both of the base portion <b>145</b> can be provided with alignment features adapted to engage complementary alignment features provided on the opposing surfaces of retainer <b>48</b> and lower insulator <b>41</b>. For example, in the present embodiment the forward facing surface of the base portion <b>145</b> is provided with a cylindrical step <b>147</b> that is coaxial with the central axis of bore <b>143</b> and that is adapted to seat within the central hole <b>106</b> of the retainer <b>48</b>. As central hole <b>106</b> is configured to be coaxial with the axis of barrel <b>21</b> when retainer <b>48</b> is attached to insulator <b>41</b>, bore <b>143</b> will also be coaxial with barrel <b>21</b>. Similarly, the rear facing surface of the base portion is provided with a cylindrical recess <b>149</b> sized to receive the pedestal <b>84</b> provided on the forward facing surface of insulator <b>41</b>, thus providing further assurance that the axis of bore <b>143</b> will be aligned with the axis of barrel <b>21</b>.

When base <b>125</b> of combination <b>121</b> is seated in bore <b>143</b>, electrodes <b>57</b> and <b>58</b> of the lamp bulb <b>59</b> pass out of the lower end of the base <b>125</b> and lamp base receiver <b>119</b>. The first electrode <b>57</b> further extends through hole <b>49</b> in the lower insulator <b>41</b> and into electrical contact with the first contact <b>55</b>. The second electrode extends into axial slot <b>85</b> provided in the forward surface of lower insulator <b>41</b> and into electrical contact with the second contact <b>83</b>. As a result, electrodes <b>57</b> and <b>58</b> are also in electrical contact with the first conductor <b>39</b> and the second conductor <b>42</b>, respectively. The electrodes <b>57</b> and <b>58</b> are frictionally held in place by contacts <b>55</b> and <b>83</b>, respectively, which in turn keeps base <b>125</b> seated against the wall of bore <b>143</b>. As a result, the alignment of filament <b>60</b> is maintained with respect to the axis of barrel <b>21</b>.

Moreover, if combination <b>121</b> is replaced with a spare lamp bulb, lamp base combination <b>121</b>, such as the one stored in spare bulb holder <b>29</b> provided in tail cap <b>22</b>, filament <b>60</b> of the spare bulb <b>59</b> will still be aligned with the axis of barrel <b>21</b>, and hence the principal axis of reflector <b>101</b> as described more fully below. This is because the center of the filament <b>60</b> of each lamp bulb has been aligned with the predetermined axis of the lamp base <b>125</b>. As a result, the center of the filament <b>60</b> of each lamp bulb will be automatically aligned with the axis of barrel <b>21</b>, and hence the principal axis of the reflector, when the base <b>125</b> is seated in bore <b>143</b>.

Although lamp base receiver <b>119</b> is shown as being formed separately from retainer <b>48</b>, it will be appreciated that lamp base receiver <b>119</b> may also be integrally formed with retainer <b>48</b>. Receiver <b>119</b> is preferably formed separately from retainer <b>48</b>, however, so that receiver <b>119</b> may be formed from a suitable metal, such as aluminum. An advantage of having a metal receiver <b>119</b> is that it will act as a heat sink. Further, as receiver <b>119</b> is in contact with the second conductor <b>42</b>, which in turn will be in contact with lip <b>95</b> of barrel <b>21</b> when the flashlight is turned on, heat will be carried away from the area surrounding bulb <b>59</b> through receiver <b>119</b> and conductor <b>42</b> to barrel <b>21</b>. In addition, because conductor <b>42</b> includes a plurality of arms <b>87</b> with barrel contacts <b>88</b>, the amount of heat that can be conducted away from lamp bulb <b>59</b> is significantly greater than in previously known switch designs that are activated by rotation of a head assembly. As a result, higher amperage bulbs may be used in flashlight <b>20</b> without risking thermal damage to insulated retainer <b>48</b> or lower insulator <b>41</b>.

The head assembly <b>23</b> is installed external to the barrel <b>21</b> by engaging threads <b>153</b> formed on the interior surface of the head <b>24</b> with mating threads formed on the exterior surface of the barrel <b>21</b>. A sealing element <b>155</b>, such as an O-ring, may be installed around the circumference of the barrel <b>21</b> adjacent to the threads to provide a water tight seal between the head assembly <b>23</b> and the barrel <b>21</b>. The substantially parabolic reflector <b>101</b> is configured to be disposed within the outermost end of the head <b>24</b>, wherein it is rigidly held in place by the lens <b>26</b> which is in turn retained by the face cap <b>25</b> which is threadedly engaged with threads <b>157</b> formed on the forward portion of the outer diameter of the head <b>24</b>. The reflector <b>101</b> is designed such that the principal axis <b>123</b> of the reflector <b>101</b> coincides with the axis of the head assembly and the axis of the barrel when the flashlight is fully assembled. As a result, filament <b>60</b> of lamp bulb <b>59</b>, which is aligned with the central axis of barrel <b>21</b>, will also be centered with respect to the principal axis of the reflector when the flashlight is fully assembled, thereby ensuring optimal optical characteristics for the flashlight <b>20</b>.

For example, by using lamp and base combination <b>121</b> in conjunction with base receiver <b>119</b>, manufacturing tolerances may be readily maintained so that the center of filament <b>60</b> is displaced by no more than 0.003 inches from the principal axis <b>123</b> of reflector <b>101</b>. It has been found, however, that tolerances may be readily maintained so that the filament <b>60</b> is displaced by 0.001 inches or less from the principal axis <b>123</b> of reflector <b>101</b> in the assembled flashlight. In general, tolerances are preferably maintained so that the center of filament <b>60</b> is disposed as close as possible to the principal axis of reflector <b>101</b> in the assembled flashlight, with coincidence being ideal.

A sealing element <b>159</b>, such as an O-ring, may be incorporated at the interface between the face cap <b>25</b> and head <b>24</b> to provide a watertight seal. A sealing element <b>161</b> may also be incorporated at the interface between the face cap <b>25</b> and the lens <b>26</b> to provide a watertight seal.

The rear-facing surface of reflector <b>101</b> is provided with an abutment <b>163</b> that surrounds the central opening formed in reflector <b>101</b> for passage of lamp bulb <b>59</b> and tubular extension <b>146</b>. Abutment <b>163</b> may, for example, comprise a concentrically formed ledge around the outer surface of reflector <b>101</b>. Alternatively, abutment <b>163</b> may comprise a plurality of ledges formed in a series of ribs or fins provided on the exterior surface of reflector <b>101</b>.

When head <b>24</b> is fully screwed onto the barrel <b>21</b> by means of the threads <b>153</b>, abutment <b>163</b> abuts against shoulder <b>113</b> of retainer <b>48</b>, urging it in a direction counter to that indicated by arrow <b>36</b>. The upper insulator receptacle <b>47</b> then pushes lamp base receiver <b>119</b> and the lower insulator <b>41</b> in the same direction, thereby providing a space between the barrel contacts <b>88</b> and the lip <b>95</b> on the forward end of the barrel <b>21</b>. The second conductor <b>42</b> is thus separated from contact with the lip <b>95</b> of the barrel <b>21</b> as shown in FIG. 3A, and the electrical circuit is opened.

Referring to FIG. 4, appropriate rotation of the head <b>24</b> about the axis of the barrel <b>21</b> causes the head assembly <b>23</b> to move in the direction of arrow <b>36</b> through the engagement threads <b>153</b>. Upon reaching the relative position indicated in FIG. 4, the head assembly <b>23</b> has progressed a sufficient distance in the direction of arrow <b>36</b> such that the reflector <b>101</b> has moved a like distance enabling the retainer <b>48</b>, the lamp base receiver <b>119</b>, and the lower insulator <b>41</b> to be moved by the urging of the spring member <b>34</b> translating the batteries <b>31</b> in the direction of the arrow <b>36</b>, to the illustrated position. In this position, the barrel contacts <b>88</b> have been brought into contact with the lip <b>95</b> on the forward end of the barrel <b>21</b>, which closes the electrical circuit.

The head assembly <b>23</b> may be rotated further so as to cause further translation of the head assembly <b>23</b>, including the reflector <b>101</b>, in the direction indicated by arrow <b>36</b>. During this operation the upper insulated retainer <b>48</b> remains in a fixed position relative to barrel <b>21</b>. Thus, the lamp bulb <b>59</b> and the optically centered filament <b>60</b> of the lamp bulb <b>59</b> also remain in a fixed position. The shifting of the reflector <b>101</b> relative to the lamp bulb <b>59</b> during this additional rotation of the head assembly produces a relative shift in the position of the filament of the lamp bulb <b>59</b> with respect to the focus of the parabola of the reflector <b>101</b>, thereby varying the dispersion of the light beam emanating from the lamp bulb <b>59</b> through the lens <b>26</b>. The shifting of the reflector <b>101</b> is substantially limited to movement along the shared axis of the barrel <b>21</b> and the reflector <b>101</b>, thus preserving the alignment of the filament <b>60</b> of the lamp bulb <b>59</b> with the principal axis of the reflector <b>101</b>.

Referring to FIGS. 2, <b>3</b>, <b>5</b> and <b>6</b>, the tail cap assembly <b>28</b> according to one of the separate aspects of the present invention is now more fully described. Tail cap assembly <b>28</b> includes a spring member <b>34</b> that generally comprises a tapered coil spring. A base coil in spring member <b>34</b> is provided with an oval shape having a major diameter that is sufficient to allow the spring member <b>34</b> to be in direct contact with the inner surface <b>30</b> of barrel <b>21</b> when the tail cap assembly is inserted in barrel <b>21</b> as shown in FIG. <b>3</b>. The minor diameter of the oval-shaped coil of spring member <b>34</b> is sized to be received by opposing ears <b>165</b> provided on the forward end of tail cap <b>22</b>. Ears <b>165</b> act as a spring seat. In the present embodiment, ears <b>165</b> are curved to follow the circumference of the forward end of tail cap <b>22</b> and are provided with lips <b>167</b> on their opposing faces. Lips <b>167</b> are designed to retain spring member <b>34</b> to tail cap <b>22</b> while allowing the major diameter of the oval-shaped coil to project out opposing openings formed between the ears <b>165</b> as best seen in FIG. <b>2</b>. When the tail cap <b>22</b> is engaged to the barrel <b>21</b>, the design of the spring member <b>34</b> allows for direct electrical contact between the case electrode <b>35</b> of the rearmost battery <b>31</b> and the inner surface <b>30</b> of the barrel <b>21</b>. As a result, tail cap <b>22</b> may be eliminated from the electrical circuit of the flashlight. This in turn eliminates the need to machine or mask the tail cap if it is coated with a non-conductive coating, such as when the tail cap is anodized or painted. Furthermore, the number of parts required in comparison to currently known tail cap assemblies for flashlights that do not include the tail cap as part of the electrical circuit is reduced.

Referring to FIGS. 3, <b>4</b> and <b>5</b> the electrical circuit of flashlight <b>20</b> according to the present embodiment of the invention will now be described. Electrical energy is conducted from the rearmost battery <b>31</b> through its center contact <b>37</b> which is in connection with the case electrode <b>36</b> of the forwardmost battery <b>31</b>. Electrical energy is then conducted from the forwardmost battery <b>31</b> through its center electrode <b>38</b> to the first conductor <b>39</b> which is coupled to the lamp electrode <b>57</b>. After passing through filament <b>60</b> of the lamp bulb <b>59</b> the electrical energy emerges through lamp electrode <b>58</b> which is coupled to the second conductor <b>42</b>. When the head assembly <b>23</b> has been rotated about the threads <b>153</b> to the position illustrated by FIG. 3, the barrel contacts <b>88</b> of second conductor <b>42</b> do not contact the lip <b>95</b> of the barrel <b>21</b>, thereby resulting in an open electrical circuit. However, when the head assembly <b>23</b> has been rotated about the threads <b>153</b> to the position illustrated in FIG. 4, the barrel contacts <b>88</b> of the second conductor <b>42</b> are now pressed against the lip <b>95</b> by the lower insulator <b>41</b> being urged in the direction of the arrow <b>36</b> by the spring member <b>34</b>. In this configuration, electrical energy may then flow from the barrel conductor <b>42</b> into to the lip <b>95</b>, through the barrel <b>21</b>, and into the spring member <b>34</b>, the spring member <b>34</b> being in electrical contact with the case electrode <b>35</b> of the rearmost battery <b>31</b>. By rotating the head assembly <b>23</b> about the threads <b>153</b> such that the head assembly <b>23</b> moves in the direction counter to that indicated by the arrow <b>36</b>, the head assembly <b>23</b> may be restored to the position illustrated in FIG. 3, thereby opening the electrical circuit and turning off the flashlight.

An additional utilization of the flashlight <b>20</b> in accordance with the present invention is achieved by rotating the head assembly <b>23</b> about the threads <b>153</b> in a direction causing the head assembly to translate relative to the barrel <b>21</b> in the direction of the arrow <b>36</b> of FIG. 3 whereby the electric circuit will be closed and the lamp bulb <b>59</b> will be illuminated. Continued rotation of the head assembly <b>23</b> in that direction will enable the head assembly <b>23</b> to be completely removed from the forward end of the flashlight <b>20</b>. By placing the head assembly <b>23</b> upon a substantially horizontal surface such that the face cap <b>25</b> rests on the surface, the tail cap <b>22</b> of the flashlight may be inserted into the head to hold the barrel <b>21</b> in a substantially vertical alignment. Since the reflector <b>101</b> is located within the head assembly <b>23</b>, the lamp bulb <b>45</b> will omit a substantially spherical or candle-like illumination, thereby providing an ambient light level.

In a preferred implementation of the illustrated embodiment, the barrel <b>21</b>, tail cap <b>22</b>, head <b>23</b>, and face cap <b>25</b>, forming all of the exterior surfaces of the flashlight <b>20</b> are manufactured from aircraft quality, heat treated aluminum, which is anodized for corrosion resistance. The sealing elements <b>33</b>, <b>155</b>, <b>159</b>, and <b>161</b> preferably provide atmospheric sealing of the interior of the flashlight <b>20</b>. All interior electrical contact surfaces are preferably appropriately machined to provide efficient electrical conduction. The reflector <b>101</b> is provided with a computer-generated parabolic reflecting surface that is vacuum aluminum metallized to ensure high precision optics.

Various embodiments of improved high quality flashlights and their respective components have been presented in the foregoing disclosure. While preferred embodiments of the herein invention have been described, numerous modifications, alterations, alternate embodiments, and alternate materials may be contemplated by those skilled in the art and may be utilized in accomplishing the various aspects of the present invention. For example, while combination <b>121</b> and lamp base receiver <b>119</b> have been illustrated in the described embodiment to be used in a particularly preferred switch design, the use of lamp base receiver <b>121</b> and combination <b>121</b> is not so restricted. Rather, the lamp base receiver and combination <b>121</b> disclosed herein may be employed in flashlights having a wide variety of other configurations and switch designs, as well as switch placements within flashlight <b>20</b>. All that is needed is for the lamp base receiver <b>119</b> to be mounted adjacent the central opening in reflector <b>101</b> so that when the base is seated in the base receiver the lamp bulb extends through the central opening in the reflector and the predetermined axis of the lamp base is aligned with the principal axis of the reflector. Since the center of the filament <b>60</b> of each lamp bulb has been aligned with the predetermined axis of the lamp base, the center of the filament <b>60</b> of each lamp bulb will be automatically aligned with principal axis of the reflector. Similarly, the switch <b>40</b> described herein may be employed in a flashlight <b>20</b> without employing the lamp and lamp base combination <b>121</b>. Likewise, the tail cap assembly <b>28</b> described herein may also be used in a wide variety of flashlight designs, including those that do not employ a switch <b>40</b> or lamp and lamp base combination <b>121</b> according to the present invention. It is envisioned that all such alternate embodiments are considered to be within the scope of the present invention as described by the appended claims.